Early Monday morning, Israel launched airstrikes against central and western Iran in response to missile attacks from Tehran, which risked dragging a wider swath of the Middle East into a regional war.

Iranian state television reported that explosions were heard in Isfahan, Karaj, Tabriz, and Tehran, but did not immediately provide further details.

Iran’s paramilitary Revolutionary Guard said Israel used air-launched ballistic missiles in the attack on Monday morning, without elaborating.

On Sunday, Israel carried out airstrikes on the southern suburbs of Beirut. In retaliation, Iran launched attacks against Israel, prompting Israel to strike Iran on Monday morning.

A senior U.S. official said that U.S. President Donald Trump had called Israel Prime Minister Benjamin Netanyahu to urge him not to retaliate immediately against Iran’s missile attacks.